The city's oldest cemetery is the final resting place for at least 1,000 early Tampa residents — pioneers, Confederate soldiers, victims of yellow fever, pirates, 13 mayors and slaves — but there might be even more.

So this week, anthropologists and students from the University of South Florida brought ground-penetrating radar and other equipment to Oaklawn Cemetery and the adjacent St. Louis Catholic Cemetery to search for and map unmarked graves.

"This is like an outdoor museum," said Jeff Moates, regional director of the Florida Public Archaeology Network. "You come here and you learn about Tampa, how the city was founded, all the people that had a role and played a part."

Oaklawn was designated as a public burial ground for "White and Slave, Rich and Poor" in 1850, when the city's population was about 500.

But many of the original grave markers were carved from cypress or other wood and rotted or disappeared over time. Tampa didn't get rail service until 1884, so importing granite headstones for the earliest graves required bringing the heavy monuments into town by some combination of sail, steamship and wagon.

What's more, during the Civil War an 8-inch shell landed in the cemetery during a naval bombardment of Tampa in 1862.

After the war, the original map of the cemetery was lost. And Oaklawn contains two mass graves — one for 102 soldiers and early settlers at Fort Brooke, which was abandoned before Oaklawn was dedicated, and another for at least 88 victims of five outbreaks of yellow fever between 1853 and 1887.

The result is a partial but colorful mosaic of local history.

One grave marker says simply:

Charles Owens

Hanged

1882

Perhaps Oaklawn's best-known headstone is for former city clerk William Ashley, who was white, and Nancy Ashley, an African-American servant and longtime companion. Historians say Oaklawn is one of the few graveyards in the nation where slaves and slave owners can be found in the same plots.

The Ashleys' marker says:

Here lies

Wm. Ashley and Nancy Ashley

Master and servant

Faithful to each other in that relation in life, in death they are not separated

Stranger, consider and be wiser.

In the grave all human distinction of race or caste mingle together in one common dust

USF researchers are using ground-penetrating radar and a magnetic gradiometer to spot anomalies in the soil or bits of metal from coffins or clothing that could mark lost graves, and GPS technology to map the site.

"What happened here happened a lot of places," said Tom Pluckhahn, an associate professor and archaeologist in USF's Department of Anthropology. "This cemetery is 150 years old. Headstones get knocked over. We've also got slave graves here that were probably never really marked very well. . . . So over time, the location of the graves becomes obscure."

The search comes amid ongoing city-supported efforts to restore the historic cemetery, including pressure-washing the stone wall surrounding Oaklawn and clearing away trash left by vagrants.

Preservationists also want to petition the National Park Service to bestow national historic landmark status on the graveyard.

Data compiled by the USF team over the next few weeks will go into a database of the site, at 606 E Harrison St. on the northern edge of downtown.

"There's an opportunity for us to bring this back and let people understand the history that is here, and how significant this cemetery is," Buckhorn said Friday.

And, for the mayor, it also was a chance to revel in a spot where history and politics come together.

Asked to roll a piece of ground-penetrating radar equipment over an area of possible unmarked graves, Buckhorn asked, "If we identify them, can we get them registered to vote?"

There is a reason why the air in Tampa Bay is filled with playoff talk. If Thursday night's 12-8 Bucs preseason win over the Jaguars is any indication, it's also going to be filled with footballs thrown by quarterback Jameis Winston.